I've found a simple solution for gaining write access to the external sdcard (/mnt/sdcard2) on Android 3.2. The sdcard is mounted r/w, but the owning group is media_rw which is linked to the WRITE_MEDIA_STORAGE permission. Unfortunately, this permission was not required for access to the external sdcard prior to 3.2 so most file management utilities do not request it when they run...meaning they only have read access to the card.

The simple solution, if you're rooted, is as follows:
1. Using a root-enabled file manager, navigate to /system/etc/permissions and make sure you have mounted the file system r/w.
2. Edit platform.xml and find the WRITE_EXTERNAL_STORAGE permission.
3. Add an additional group definition for this permission...<group gid="media_rw" />
4. Save the changes to the file.
5. Restart your tablet.

After this change, any apps that request the WRITE_EXTERNAL_STORAGE permission (which includes almost anything that access either of the sdcards) will gain group membership in both sdcard_rw AND media_rw, giving them r/w access to both sdcard filesystems.

I've found a simple solution for gaining write access to the external sdcard (/mnt/sdcard2) on Android 3.2. The sdcard is mounted r/w, but the owning group is media_rw which is linked to the WRITE_MEDIA_STORAGE permission. Unfortunately, this permission was not required for access to the external sdcard prior to 3.2 so most file management utilities do not request it when they run...meaning they only have read access to the card.

The simple solution, if you're rooted, is as follows:
1. Using a root-enabled file manager, navigate to /system/etc/permissions and make sure you have mounted the file system r/w.
2. Edit platform.xml and find the WRITE_EXTERNAL_STORAGE permission.
3. Add an additional group definition for this permission...<group gid="media_rw" />
4. Save the changes to the file.
5. Restart your tablet.

After this change, any apps that request the WRITE_EXTERNAL_STORAGE permission (which includes almost anything that access either of the sdcards) will gain group membership in both sdcard_rw AND media_rw, giving them r/w access to both sdcard filesystems.

But, I have to frickin' ask: ... Is this a bug? ...
Do all Honeycomb devices have this problem??

Not a bug. Its a design change with honeycomb that very few (if any) app developers have caught up with. I think that at least some tablet makers have modified that .xml file in their stock firmware, but certainly not all of them.

The simple solution, if you're rooted, is as follows:
1. Using a root-enabled file manager, navigate to /system/etc/permissions and make sure you have mounted the file system r/w.
2. Edit platform.xml and find the WRITE_EXTERNAL_STORAGE permission.
3. Add an additional group definition for this permission...<group gid="media_rw" />
4. Save the changes to the file.
5. Restart your tablet.

After this change, any apps that request the WRITE_EXTERNAL_STORAGE permission (which includes almost anything that access either of the sdcards) will gain group membership in both sdcard_rw AND media_rw, giving them r/w access to both sdcard filesystems.

I have the same problem and this tip work for me. Thank u for useful tip .

I'm afraid this didn't work for me. I'm a bit new to working with an android device, but I have rooted the unit, and then acquired root explorerer, and then carefully edited the xml file noted. I rebooted and still cannot write to the extSD.

When I went back into the xml file, I noted that in place of two "group" tags (including the one I added for "media_rw"), only the one I added was in the permissions group noted. The one that was there when I edited is now gone. Even root explorer was not able to test create a new folder on the extSD.

Any suggestions?

CORRECTION: I can now navigate to the extSD and create folders via root explorer. But so far, other file managers (beyond the systems default) do not seem able to do so. Strange (to me). This also means I cannot copy and paste files either except through root explorer (which is sort of unfriendly to this newb vs. other file managers).

Last edited by Sigilist; 20th January 2012 at 04:06 PM.
Reason: UPDATE

I'm afraid this didn't work for me. I'm a bit new to working with an android device, but I have rooted the unit, and then acquired root explorerer, and then carefully edited the xml file noted. I rebooted and still cannot write to the extSD.

When I went back into the xml file, I noted that in place of two "group" tags (including the one I added for "media_rw"), only the one I added was in the permissions group noted. The one that was there when I edited is now gone. Even root explorer was not able to test create a new folder on the extSD.

Any suggestions?

My solution was to use a different text editor than stock (used "Text Edit," free through market) after using Root Explorer to set the folder to r/w (read/write). I had no luck using the stock editor...

Following the instruction, I can write to the External-SD card with Root Explorer, but if you reboot your table, whatever in there would be gone...

Does it happens to You?

Thanks

It does not.

I almost forgot this important step when I edited the file:

"The simple solution, if you're rooted, is as follows:
1. Using a root-enabled file manager, navigate to /system/etc/permissions and make sure you have mounted the file system r/w.
2. Edit platform.xml and find the WRITE_EXTERNAL_STORAGE permission.
3. Add an additional group definition for this permission...<group gid="media_rw" />4. Save the changes to the file.
5. Restart your tablet."

"The simple solution, if you're rooted, is as follows:
1. Using a root-enabled file manager, navigate to /system/etc/permissions and make sure you have mounted the file system r/w.
2. Edit platform.xml and find the WRITE_EXTERNAL_STORAGE permission.
3. Add an additional group definition for this permission...<group gid="media_rw" />4. Save the changes to the file.
5. Restart your tablet."

Check to make sure you are saving the edit before you reboot.

Oh yeah!!! of course, if it doesn't, then it can't be created on the new files or folder in external storage.

Double check again, created the new text file on the root of "extStorages", then reboot.... result: File is gone

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